<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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         <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <!-- 模板内容 -->
    <div id="demo">
        <div class="box" :class="[isA ? classA:'',classB]">三元运算符</div>
      
    </div>
    <!-- js -->
    <script>
        var demo = new Vue({
            el:"#demo",
            data:{
                classA:'textColor',
                classB:'textSize',
                isA:false
               
            }
        })
    </script>
</body>
</html>